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<!-- DFIN New ActiveDisclosure (SM) XBRL Schema Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date :2026-05-11T15:42:59.1605+00:00 -->
<!-- Copyright (c) 2026 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PercentageAddedToCostOfGoodsThatRepresentsPriceOfManufacturedComponents_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Added to Cost of Goods that represents Price of Manufactured Components</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PercentageAddedToCostOfGoodsThatRepresentsPriceOfManufacturedComponents_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage added to cost of goods that represents price of manufactured components</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonUnitOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Unit, Outstanding</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableExpenseReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursable expense received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableExpenseReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursable expenses received</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedPersonnelRelatedExpensesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued personnel related expenses</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityShellCompany_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Shell Company</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAdvance_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaboration advance.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAdvance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaboration advance</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfNonCashCollaborationsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of non-cash collaborations revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfNonCashCollaborationsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of non-cash collaboration revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfNonCashCollaborationsRevenue_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Amortization of non-cash collaboration revenue</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableInternalCostsAndOutOfPocketCostsIncurred_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursable Internal Costs and Out-of-Pocket Costs Incurred</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableInternalCostsAndOutOfPocketCostsIncurred_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursable internal costs and out-of-pocket costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExtendedReasearchTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Extended research term.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModificationUnderAscSevenOneEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Modification under asc seven one eight.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModificationUnderAscSevenOneEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Modification Under ASC Seven One Eight [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModificationUnderAscSevenOneEightMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Modification Under ASC 718</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Significant Accounting Policies [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SignificantAccountingPoliciesTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Significant Accounting Policies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimburableInternalCostsAndOutOfPocketCostsIncurredPayableInQuarterlyInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursable internal costs and out-of-pocket costs incurred payable in quarterly installments.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimburableInternalCostsAndOutOfPocketCostsIncurredPayableInQuarterlyInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursable Internal Costs and Out-of-Pocket Costs Incurred Payable in Quarterly Installments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimburableInternalCostsAndOutOfPocketCostsIncurredPayableInQuarterlyInstallments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursable internal costs and out-of-pocket costs payable in quarterly installments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock options, number of shares granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsInterestsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Profits interests.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsInterestsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Profits Interests [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsInterestsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Profits Interests</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEarningsPerShareBasicAndDilutedTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Basic and Diluted Net Loss Per Share Attributable To Common Stockholders</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment, Name [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments Classified by Contractual Maturity Date [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Amortized Cost and Fair Value of Available-for-sale Marketable Securities by Contractual Maturity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss per share attributable to common stockholders - basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentCostReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Research and development cost received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentCostReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research And Development Cost Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentCostReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development costs received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockPurchaseAdditional_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock purchase additional.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockPurchaseAdditional_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional purchase of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockPurchaseAdditional_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Purchase Additional</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherCollaborationRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other collaboration revenue .</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherCollaborationRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Collaboration Revenue [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherCollaborationRevenueMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Profit Interests, Outstanding, Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Profit Interests, Outstanding, Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PercentageOfAppointmentRight_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Percentage of Appointment Right</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PercentageOfAppointmentRight_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of appointment right.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PercentageOfAppointmentRight_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of appointment right</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentOptionAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Development, option and license agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentOptionAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Development, Option and License Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentOptionAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Development, Option and License Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accounts Receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccountsReceivable_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Adjustments to reconcile net loss to net cash used in operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EquityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EquityTable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentAndRegulatoryMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Development and regulatory milestone payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentAndRegulatoryMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Development And Regulatory Milestone Payment Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentAndRegulatoryMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Development and regulatory milestones payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Future regulatory approval milestone payments received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Future Regulatory Approval Milestone Payments Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future regulatory approval milestone payments received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeesEligibleAnnualCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Employee's eligible annual compensation.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeesEligibleAnnualCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee's eligible annual compensation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExploratoryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exploratory program member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExploratoryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exploratory Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExploratoryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exploratory Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders' equity (deficit):</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntitySmallBusiness_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Small Business</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A-2 Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A-2 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA2PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A-2 Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedResearchAndDevelopmentExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued research and development expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedResearchAndDevelopmentExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Research and Development Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedResearchAndDevelopmentExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued research and development expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Retained Earnings (Accumulated Deficit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings (Accumulated Deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TemporaryEquityStockIssuedValueConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Temporary equity stock issued value conversion of redeemable convertible preferred stock to common stock upon initial public offering.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TemporaryEquityStockIssuedValueConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity Stock Issued Value Conversion Of Redeemable Convertible Preferred Stock To Common Stock Upon Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TemporaryEquityStockIssuedValueConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of redeemable convertible preferred stock to common stock upon initial public offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna DT Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Moderna DT Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna DT program.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceInitialPublicOffering_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Issuance Initial Public Offering</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsShareBasedPaymentsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Text Block]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Organization, Consolidation and Presentation of Financial Statements [Abstract]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AffiniTTherapeuticsIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Affini-T Therapeutics, Inc.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AffiniTTherapeuticsIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Affini-T</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Exchanged For Vested And Unvested Common Stock In Connection With The Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Profits Interests, Exchanged for vested and unvested common stock in connection with the Reorganization</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IncreaseDecreaseInDeferredRevenueAndCollaborationAdvances_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase (decrease) in deferred revenue and collaboration advances.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IncreaseDecreaseInDeferredRevenueAndCollaborationAdvances_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue and collaboration advance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities and Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesAndStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities, Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Postal Zip Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Operating Lease Liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingCodmProfitLossMeasureHowUsedDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment reporting, CODM, profit (loss) measure, how used, description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentReceivedAsCollaborationConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value of Investment Received as Collaboration Consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentReceivedAsCollaborationConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value of investment received as collaboration consideration.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentReceivedAsCollaborationConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of investment received as collaboration consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePayment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePayment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">exercise payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePayment_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">exercise payment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MetagenomiIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Metagenomi Inc.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MetagenomiIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Metagenomi Inc [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MetagenomiIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Metagenomi Inc</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, Address Line One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hierarchy and NAV [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Amortized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDateAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Amortized Cost, Total available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Carrying Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Redeemable convertible preferred stock: zero shares authorized, issued and outstanding as of September 30, 2024; 41,813,375 shares authorized, issued and outstanding as of December 31, 2023; liquidation preference of $352,044 as of December 31, 2023</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityCarryingAmountAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Carrying Amount, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NonRefundableUpfrontCollaborationPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non refundable upfront collaboration payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NonRefundableUpfrontCollaborationPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non refundable upfront collaboration payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedPaymentArrangementValuationTechniqueExtensibleEnumeration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Valuation Technique [Extensible Enumeration]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Right-of-Use Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease right-of-use assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">OCI, Debt Securities, Available-for-Sale, Gain (Loss), after Adjustment and Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrealized loss on available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AdditionalExploratoryCostReimbursementsAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional exploratory cost reimbursements amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AdditionalExploratoryCostReimbursementsAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Additional exploratory cost reimbursements amount.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentType_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Type</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentSuppliesAndServices_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Supplies and Services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentSuppliesAndServices_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Research and development supplies and services.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ResearchAndDevelopmentSuppliesAndServices_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development supplies and services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCentralIndexKey_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Central Index Key</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Amortized Cost, Unrealized Gains (Losses) and Fair Value of Available-for-sale Marketable Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Initial Public Offering Costs Included In Accounts Payable, Accrued Expenses And Other Current Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Initial public offering costs included in accounts payable, accrued expenses and other current liabilities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Initial public offering costs included in accounts payable, accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial public offering costs included in accounts payable, accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfContractConsiderationAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amortization of contract consideration amount.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfContractConsiderationAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of contract consideration amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsDebtAndEquitySecuritiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments, Debt and Equity Securities [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursable expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursable expenses.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursableExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursable expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net increase (decrease) in cash, cash equivalents and restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sales-based milestones to be received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sales-Based Milestones to be Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales-based milestones to be received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A-1 Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A 1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A-1 Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharingPayables_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cost sharing payables.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharingPayables_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost Sharing Payables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharingPayables_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost sharing payables</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income (loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Other comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReductionInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reduction in variable consideration.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReductionInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reduction in Variable Consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReductionInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reduction in variable consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Amortized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Amortized Cost, Total available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAmortizedCostBasis_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortized Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Fair Value, Total available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FututeSalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fututre sales-based milestones to be received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FututeSalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Futute sales based milestones to be received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FututeSalesBasedMilestonesToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Futute sales-based milestones to be received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaTxIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna TX, Inc.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaTxIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna TX Inc [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaTxIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Moderna TX, Inc</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaTxIncMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Moderna</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Stock options, number of shares outstanding beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Stock options, number of shares outstanding ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Nonvested, Number of Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StockSharesCanceled_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock shares canceled.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StockSharesCanceled_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Shares Canceled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StockSharesCanceled_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares canceled</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Upfront payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Upfront Payment Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Upfront payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonUnitAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Unit, Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonUnitAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common units, authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaRtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna RT program.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaRtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna RT Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaRtProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Moderna RT Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCanceledInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangements by share based payment award options canceled in connection with the reorganization weighted average exercise price.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCanceledInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangements By Share Based Payment Award Options Canceled In Connection With The Reorganization Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsCanceledInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average Threshold amount, Canceled in connection with the Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Current Fiscal Year End Date</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Long-Term Debt Instruments [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentQuarterlyReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Quarterly Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, State or Province</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Number of Shares, Outstanding, Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Number of Shares, Outstanding, Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfSubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary of LLC or LP [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_EquityMethodInvesteeNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment, Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentOwnedBalanceShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investment Owned, Balance, Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentOwnedBalanceShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares investment owned</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Preferred Stock, Shares Outstanding, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Preferred Stock, Shares Outstanding, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Comprehensive Income (Loss), Net of Tax, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Comprehensive loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrealized Gains</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedGainBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Gain, before Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Capital Shares Reserved for Future Issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock shares reserved/available for future issuance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Shares Converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockSharesConverted1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Outstanding shares converted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaboration agreement upfront payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaboration Agreement Upfront Payment Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaboration agreement upfront payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Classification of Share-based Compensation Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfEmployeeServiceShareBasedCompensationAllocationOfRecognizedPeriodCostsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Summary of Classification of Stock-based Compensation Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfessionalFees_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Professional services and consulting</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfessionalFees_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Professional Fees</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableAccruedLiabilitiesAndOtherLiabilitiesDisclosureCurrentTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued Expenses and Other Current Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedRestrictedCommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unvested Restricted Common Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedRestrictedCommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unvested Restricted Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedRestrictedCommonStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Unvested restricted common stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndOtherIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest and Other Income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndOtherIncome_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest and other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EstimatedTransactionPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Estimated transaction price.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EstimatedTransactionPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Estimated Transaction Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EstimatedTransactionPrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated transaction price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Significant Agreements</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Comprehensive Income (Loss), Net of Tax [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTaxPeriodIncreaseDecreaseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income (loss):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockWarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Warrant Exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockWarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock warrant exercisable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockWarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds from Sale and Maturity of Marketable Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maturities of available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Event</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursementForResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursement for research costs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursementForResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursement for Research Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReimbursementForResearchCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursement for research costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ContractConsiderationTransactionCost_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract consideration transaction cost.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ContractConsiderationTransactionCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract consideration transaction cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ContractConsiderationTransactionCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transaction cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IonisMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Ionis member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IonisMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Ionis [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IonisMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ionis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Assets, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtSecuritiesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Long term investments.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Investments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_LongTermInvestmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableforsaleSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total Available-for-sale Marketable Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableforsaleSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Available-for-Sale Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">AOCI Attributable to Parent [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Other Comprehensive Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Future development milestone payments to be received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Future Development Milestone Payments to be Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future development milestone payments to be received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCashAndCashEquivalentsCashAndCashEquivalentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Value, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock: $0.0001 par value; 10,000,000 shares authorized and zero shares issued and outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MinimumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted- Average Grant Date Fair Value, Granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancialInstrumentAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instrument [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of Operating Profit (Loss) from Segments to Consolidated [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 3 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel3Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 3</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Assets Measured on Recurring Basis [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Financial Assets Measured at Fair Value on Recurring Basis</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities, Current [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Current liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales based milestones received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Sales based milestones received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sales Based Milestones Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherOwnershipInterestsUnitsAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Ownership Interests, Units Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherOwnershipInterestsUnitsAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Profit interests, authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance, (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance, (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accounts Receivable, after Allowance for Credit Loss, Current, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, after Allowance for Credit Loss, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingencies_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments and contingencies (Note 8)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Weighted- Average Grant Date Fair Value, Outstanding, Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Weighted- Average Grant Date Fair Value, Outstanding, Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">General and Administrative Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General and Administrative Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableGrossCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts receivable, gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsReceivableGrossCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Receivable, before Allowance for Credit Loss, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ChangeInAccountingEstimateTypeDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Effect of Change in Accounting Estimate, Type [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Forecast [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioForecastMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forecast</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasuryBillSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Treasury Bill Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasuryBillSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Treasury Bills</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaCollaborationAgreementAndModernaConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna collaboration agreement and moderna convertible promissory note agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaCollaborationAgreementAndModernaConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna collaboration agreement and moderna convertible promissory note agreement [member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaCollaborationAgreementAndModernaConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Moderna Collaboration Agreement and Moderna Convertible Promissory Note Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NumeratorAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Numerator.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NumeratorAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Numerator [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NumeratorAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Numerator:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ContractConsiderationAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract consideration amount.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ContractConsiderationAmount_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract consideration amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Capital Expenditures Incurred but Not yet Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CapitalExpendituresIncurredButNotYetPaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchases of property and equipment included in accounts payable, accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss), Including Portion Attributable to Noncontrolling Interest</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProfitLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Income Taxes, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccruedIncomeTaxesCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax payable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">2024 employee stock purchase plan.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">2024 Employee Stock Purchase Plan [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ESPP</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EmployeeStockPurchasePlanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Weighted-average common shares outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average common shares outstanding - basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_StatementScenarioAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FinalPaymentToBeForfeited_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Final payment to be forfeited.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FinalPaymentToBeForfeited_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Final Payment To Be Forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FinalPaymentToBeForfeited_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Final payment to be forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Plan Modification, Incremental Cost</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated total modification expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_VittoriaInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">ViTToria Investment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_VittoriaInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">ViTToria Investment [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_VittoriaInvestmentMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ViTToria investment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AnnualResearchAndDevelopmentCostsReimbursement_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Annual research and development costs reimbursement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AnnualResearchAndDevelopmentCostsReimbursement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Annual Research And Development Costs Reimbursement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AnnualResearchAndDevelopmentCostsReimbursement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Annual research and development costs reimbursement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsequent Events</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">APIC, Share-Based Payment Arrangement, Increase for Cost Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfCollaborationAdvanceExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amortization of collaboration advance expense.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfCollaborationAdvanceExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amortization of Collaboration Advance Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmortizationOfCollaborationAdvanceExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of collaboration advance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity, Attributable to Parent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders' equity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Par or Stated Value Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, par value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Basis of Accounting, Policy [Policy Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_BasisOfAccountingPolicyPolicyTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Basis of Presentation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Stockholders' Equity [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashEquivalentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Equivalents [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashEquivalentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Amounts Classified as Cash Equivalents</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_UseOfEstimates_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Use of Estimates</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WeightedAverageNumberOfSharesOutstandingBasicBeforeAdjustments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average common shares outstanding</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NumberOfSharesOfCommonStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of shares of common stock.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address, City or Town</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExtendedResearchTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Extended research terms.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExtendedResearchTerms_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Extended research term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Reportable Segments</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_SecurityExchangeName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Security Exchange Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_BrianCThomasPhDMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Brian C. Thomas, Ph. D [Member]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityBankruptcyProceedingsReportingCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Bankruptcy Proceedings, Reporting Current</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted Stock Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockUnitsRSUMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock Units (RSUs) [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Debt Securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ForeignCorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Security, Corporate, Non-US [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Redeemable Convertible Preferred Units [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable Convertible Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Security, Excluded EPS Calculation [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred units.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Units [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredUnitsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_VestingAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vesting [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Class of Stock [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingReconcilingItemForOperatingProfitLossFromSegmentToConsolidatedLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Equity consideration shares received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Upfront equity consideration shares received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Upfront Equity Consideration Shares Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Upfront equity consideration shares received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Moderna</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Liabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Government Debt Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USGovernmentDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Government Bonds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CoDevelopAndCoCommercializeLicensedProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Co-develop and co-commercialize the licensed products member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CoDevelopAndCoCommercializeLicensedProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Co-Develop and Co-Commercialize Licensed Products [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CoDevelopAndCoCommercializeLicensedProductsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Co-Develop and Co-Commercialize Licensed Products</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financial Instruments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EstimatedContractConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Estimated contract consideration.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_EstimatedContractConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Estimated contract consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInDeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantsPurchasedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrants purchased price per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantsPurchasedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrants Purchased Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantsPurchasedPricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants purchased price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Restricted Cash, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedCash_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RestrictedStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Weighted Average Number of Shares Outstanding, Diluted, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number of Shares Outstanding, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average common shares outstanding - diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AggregatePurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate share purchase amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AggregatePurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Aggregate purchase price.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AggregatePurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Aggregate Purchase Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityFileNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity File Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OptionPriceEstimatedFairValuePercentageOnDateOfGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Option price estimated fair value percentage on date of grant.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OptionPriceEstimatedFairValuePercentageOnDateOfGrant_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Option price estimated fair value percentage on date of grant</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherIncomeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Income Expense [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherIncomeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other income expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherIncomeExpenseMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Income Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CoverAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cover [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense and Other Assets, Current</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Number of Shares, Forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentTypeCategorizationMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ScenarioUnspecifiedDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Scenario [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">US Treasury Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_USTreasurySecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">U.S. Treasury Bills</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Number of Operating Segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NumberOfOperatingSegments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating segment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonSharesOfAffiniTReceivedForCollaborationRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common shares of Affini-T received for collaboration revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonSharesOfAffiniTReceivedForCollaborationRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common shares of Affini-T received for collaboration revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonSharesOfAffiniTReceivedForCollaborationRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common shares of Affini-T received for collaboration revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Disclosure [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SegmentReportingDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment Information</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">General and Administrative Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">General and Administrative Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General and administrative</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series B Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series B Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SeriesBPreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Series B Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonvested Restricted Stock Shares Activity [Table Text Block]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Including Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Liquidation Preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liquidation preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquityLiquidationPreference_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Aggregate Liquidation Preference</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ManufacturedComponentsProceeds_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Manufactured components proceeds.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ManufacturedComponentsProceeds_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Manufactured Components Proceeds</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Forfeitures and Expirations in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresAndExpirationsInPeriod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Profits Interests, Forfeited and expired</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event [Table]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Expense</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Stock options, weighted average exercise price outstanding ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock options, weighted average exercise price outstanding beginning balance</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WeightedAverageNumberOfUnvestedShares_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Weighted average number of unvested shares.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WeightedAverageNumberOfUnvestedShares_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Weighted Average Number Of Unvested Shares</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WeightedAverageNumberOfUnvestedShares_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Weighted-average unvested shares of common stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Estimated fair value of shares received as equity consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Upfront equity consideration received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Upfront Equity Consideration Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UpfrontEquityConsiderationReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Upfront equity consideration received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Convertible promissory note agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Promissory Note Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ConvertiblePromissoryNoteAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Promissory Note Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLevel3FinancialAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in fair value of Level 3 financial assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLevel3FinancialAssets_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in fair value of Level 3 financial assets.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SelectedTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Selected target member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SelectedTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Selected Target [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SelectedTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Selected Target</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerAsset_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Contract assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInContractWithCustomerAsset_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Contract with Customer, Asset</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Depreciation, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Depreciation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-Term Investments, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Long-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Carrying value of investment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_LongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Shares, Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Common Stock, Shares, Outstanding, Beginning Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Common Stock, Shares, Outstanding, Ending Balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Shares of common stock outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current portion of operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborative Arrangement and Arrangement Other than Collaborative [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transaction price allocated to remaining performance obligations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligation_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Remaining performance obligation as revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentTransitionReport_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingExpenses_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total operating expenses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Change in fair value included in other income (expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Change in fair value of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Change in fair value of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in fair value of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Change in fair value of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ChangeInFairValueOfLongTermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Research and Development Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Research and Development Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Research and development</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ResearchAndDevelopmentExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Research and development supplies and services</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Asset Impairment Charges, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Impairment Charges</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetImpairmentCharges_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on fixed assets write-off</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Conversion of Stock, Amount Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ConversionOfStockAmountIssued1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredBonusAndProfitSharingArrangementIndividualContractTypeOfDeferredCompensationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Bonus and Profit Sharing Arrangement, Individual Contract, Type of Deferred Compensation [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Cash Flows [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, New Issues</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with initial public offering, net of issuance costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Profits Units Activity and Stock Option Activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Option, Activity [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PurchaseOfPreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred shares purchased</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PurchaseOfPreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase of preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PurchaseOfPreferredStock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase of Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancingReceivableAccruedInterestWriteoff_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Financing Receivable, Accrued Interest, Writeoff</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FinancingReceivableAccruedInterestWriteoff_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Written off accrued interest receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Option, Changes in Fair Value, Gain (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in fair value of investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueOptionChangesInFairValueGainLoss1_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Gain (loss) related to changes in fair value of investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share [Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Loss Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TechnologyMilestoneFeesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Technology milestone fees received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TechnologyMilestoneFeesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Technology Milestone Fees Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TechnologyMilestoneFeesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Technology milestone fees related to preclinical research objectives</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Shares, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharesIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureSalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Potential future Sales based milestones received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureSalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Potential future sales based milestones received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureSalesBasedMilestonesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Potential future sales based milestones received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentRegulatoryAndSalesMilestonePayments_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Development regulatory and sales milestone payments.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentRegulatoryAndSalesMilestonePayments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Development Regulatory And Sales Milestone Payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DevelopmentRegulatoryAndSalesMilestonePayments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Development, regulatory and sales milestone payments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Milestone payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Milestone Payment Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_MilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Upfront payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Available-for-Sale Securities, Debt Maturities [Abstract]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DescriptionOfTerminationOfRoyaltyTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Description of termination of royalty term.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DescriptionOfTerminationOfRoyaltyTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Description of termination of royalty term</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StrategicCollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Strategic collaboration and license agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StrategicCollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Strategic Collaboration and License Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_StrategicCollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Strategic Collaboration and License Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Document Fiscal Year Focus</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AtTheMarketSalesAgreementRemainingCapacity_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">ATM Sales Agreement Remaining Capacity.</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from investing activities</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountsPayableCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable, Current</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A-3Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A-3Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA3PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A-3 Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CertainVestingConditionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Certain vesting conditions.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CertainVestingConditionsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Certain Vesting Conditions</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrant exercisable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Warrant Exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WarrantExercisable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrant exercisable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred Revenue, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Change in Accounting Principle, Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePaymentReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise payment receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePaymentReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Exercise Payment Receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ExercisePaymentReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Exercise payment receivable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsUnitsActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Profits units activity.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsUnitsActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Profits units activity [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitsUnitsActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Profits Units Activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueDisclosuresAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Disclosures [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementInitialResearchTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaboration agreement initial research term.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementInitialResearchTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaboration Agreement Initial Research Term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAgreementInitialResearchTerm_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial research term</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommitmentsAndContingenciesDisclosureAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Commitments and Contingencies Disclosure [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net Income (Loss) Available to Common Stockholders, Basic, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Net Income (Loss) Available to Common Stockholders, Basic</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss attributable to common stockholders</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OptionExerciseFeePaid_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Option exercise fee paid.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OptionExerciseFeePaid_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Option Exercise Fee Paid</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OptionExerciseFeePaid_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Option exercise fee paid per target</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IncreaseInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increase in variable consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IncreaseInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase In Variable Consideration</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IncreaseInVariableConsideration_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase in variable consideration.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecognized compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Assets, Fair Value Disclosure, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AssetsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Sale of Stock [Axis]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PurchaseOfPreferredStockAdditional_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase of preferred stock additional.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PurchaseOfPreferredStockAdditional_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Purchase of Preferred Stock Additional</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureTargetSelectionFee_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Potential future target selection fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureTargetSelectionFee_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Potential future target selection fee.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfNonvestedRestrictedStockUnitsActivityTableTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Restricted Stock Unit Activity</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CatchUpThresholdAmountBasedOnEstimatedFairValueOfCommonUnit_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Catch-up threshold amount based on estimated fair value of common unit.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CatchUpThresholdAmountBasedOnEstimatedFairValueOfCommonUnit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Catch-up threshold amount based on estimated fair value of common unit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Investing Activity, Including Discontinued Operation</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentPurchasedInPreferredStockPurchaseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair value of investment purchased in preferred stock purchase agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentPurchasedInPreferredStockPurchaseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value of Investment Purchased in Preferred Stock Purchase Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FairValueOfInvestmentPurchasedInPreferredStockPurchaseAgreement_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Fair value of investment purchased in preferred stock purchase agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_Security12bTitle_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title of 12(b) Security</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Conversion of Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion of redeemable convertible preferred stock to common stock upon initial public offering</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted- Average Grant Date Fair Value, Forfeited</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsAmortizedCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, after Year One Through Five</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_MoneyMarketFundsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Money Market Funds [Member]</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt Securities, Available-for-Sale, Allowance for Credit Loss, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleAllowanceForCreditLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Debt Securities, Available-for-Sale, Allowance for Credit Loss, Beginning Balance</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A-4 Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A-4 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesA4PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A-4 Preferred Units</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProvisionForIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Provision for income taxes.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProvisionForIncomeTaxes_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other non-current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Fair Value, Maturity, Allocated and Single Maturity Date, after Year One Through Five</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value, Maturing in one to five years</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in operating assets and liabilities:</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmendmentToLlcAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Amendment to llc agreement.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmendmentToLlcAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Amendment To LLC Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AmendmentToLlcAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amendment To LLC Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockIssuableUponConversionOfRedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock issuable upon conversion of redeemable convertible preferred stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockIssuableUponConversionOfRedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Issuable Upon Conversion Of Redeemable Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockIssuableUponConversionOfRedeemableConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common Stock Issuable Upon Conversion of Redeemable Convertible Preferred Stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Outstanding, Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Weighted-Average Threshold Amount, Outstanding, Beginning balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Weighted-Average Threshold Amount, Outstanding, Ending balance</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Including Option Exercised</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Proceeds, Issuance of Shares, Share-Based Payment Arrangement, Including Option Exercised, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of common stock under the equity incentive plan and ESPP</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSalePurchasedWithCreditDeteriorationAmountAtPurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Debt Securities, Available-for-Sale, Purchased with Credit Deterioration, Amount at Purchase Price, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSalePurchasedWithCreditDeteriorationAmountAtPurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Purchased with Credit Deterioration, Amount at Purchase Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSalePurchasedWithCreditDeteriorationAmountAtPurchasePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deterioration in creditworthiness of issuers of available-for-sale securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring and Nonrecurring [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid-in Capital [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapitalMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional Paid-In Capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Accrued Liabilities and Other Operating Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilitiesAndOtherOperatingLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued expenses and other current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_TradingSymbol_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Trading Symbol</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_VestedProfitsInterestsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Vested profits interests.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_VestedProfitsInterestsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Vested Profits Interests</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Amortized Cost, Maturity, Allocated and Single Maturity Date, Year One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearAmortizedCost_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortized Cost, Maturing within one year</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventTypeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Event Type [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetSelectionFee_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Target selection fee.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetSelectionFee_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Target Selection Fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetSelectionFee_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Target selection fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NonRefundableUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Non refundable upfront payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NonRefundableUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Non Refundable Upfront Payment Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_NonRefundableUpfrontPaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-refundable upfront payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Recurring [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementsRecurringMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recurring</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityExTransitionPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Ex Transition Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndDebtExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Interest and Debt Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndDebtExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Interest and Debt Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InterestAndDebtExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest and other</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Components [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RemeasurementOfOperatingRightOfUseAssetAndLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Remeasurement of operating right-of use asset and lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RemeasurementOfOperatingRightOfUseAssetAndLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Remeasurement of operating right-of use asset and lease liability.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RemeasurementOfOperatingRightOfUseAssetAndLeaseLiability_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Remeasurement of operating right-of use asset and lease liability</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total other income, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total other income, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByAssetClassAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Asset Class [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_LicenseFee_lbl" xlink:role="http://www.xbrl.org/2003/role/label">License fee</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_LicenseFee_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">License fee.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">IPO [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IPOMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Initial Public Offering</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsidiaryOfLimitedLiabilityCompanyOrLimitedPartnershipLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary of Limited Liability Company or Limited Partnership [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonUnitIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Unit, Issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonUnitIssued_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common units, issued</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangements by share based payment award options exchanged for vested and unvested common stock in connection with the reorganization weighted average exercise price.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangements By Share Based Payment Award Options Exchanged For Vested And Unvested Common Stock In Connection With The Reorganization Weighted Average Exercise Price</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganizationWeightedAverageExercisePrice_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted-average Threshold amount, Exchanged for vested and unvested common stock in connection with the Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Employee Stock Purchase Plans</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares issued under ESPP plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesEmployeeStockPurchasePlans_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Issuance of common stock under employee stock purchase plan (ESPP) (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Expiration Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expiration period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireLongtermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchases of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireLongtermInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Long-Term Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquireLongtermInvestments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of long-term investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockVotingRights_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock voting right description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockVotingRights_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Voting Rights</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DtCoCoProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">DT Co-Co Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DtCoCoProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">DT Co-Co Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DtCoCoProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">DT Co-Co program.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_MaximumMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RangeAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statistical Measurement [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Contract with Customer, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ContractWithCustomerLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue, non-current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CommonStockValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock, Value, Issued</link:label>
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          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualExcludingShareBasedPaymentsAndPostretirementBenefitsByTypeOfDeferredCompensationAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Bonus and Profit Sharing Arrangements, Individual Contracts, Type of Deferred Compensation [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DescriptionOfHybridInstrumentsAccountedForAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Description of Hybrid Instruments Accounted for at Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DescriptionOfHybridInstrumentsAccountedForAtFairValue_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Description of hybrid instruments accounted for at fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockForFutureIssuanceDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Common stock for future issuance description.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CommonStockForFutureIssuanceDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Common stock for future issuance description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future regulatory approval milestone payments received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Future regulatory approval milestone payment received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryApprovalMilestonePaymentReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Future regulatory approval milestone payment received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganization_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Issuance of common stock and restricted common stock in exchange for profits interests upon reorganization.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganization_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganization_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock and restricted common stock in exchange for profits interests upon Reorganization</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Future regulatory milestone payments to be received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Future Regulatory Milestone Payments to be Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureRegulatoryMilestonePaymentsToBeReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future regulatory milestone payments to be received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RoyaltyTermExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Royalty term expiration period.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RoyaltyTermExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Royalty term expiration period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_RoyaltyTermExpirationPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Royalty term expiration period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CatchUpMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Catch up.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CatchUpMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Catch Up [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CatchUpMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Catch-Up</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PreferredStockSharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock, authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series A Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series A Convertible Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesAConvertiblePreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series A convertible preferred stock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitInterestUnitMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Profit interest unit.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitInterestUnitMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Profit Interest Unit [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ProfitInterestUnitMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Profit Interest Unit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Maturity, Allocated and Single Maturity Date, Fair Value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleSecuritiesDebtMaturitiesSingleMaturityDate_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Fair Value, Total available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Option</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EmployeeStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityRegistrantName_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Registrant Name</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">future developmental milestone payments received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Future Developmental Milestone Payments Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_FutureDevelopmentalMilestonePaymentsReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Future developmental milestone payments received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Target One</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Target one member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetOneMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Target One [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale, Accumulated Gross Unrealized Loss, before Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AvailableForSaleDebtSecuritiesAccumulatedGrossUnrealizedLossBeforeTax_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Unrealized Losses</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Voluntary Filers</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharePercentageDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Cost - share percentage description.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharePercentageDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cost - Share Percentage Description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CostSharePercentageDescription_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost - share percentage description</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Other Nonoperating Income (Expense), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Nonoperating Income (Expense)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OtherNonoperatingIncomeExpense_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other expense, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Additional Paid in Capital, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid in Capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AdditionalPaidInCapital_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional paid-in-capital</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_SubsequentEventsAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Subsequent Events [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_JSCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">JSC</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_JSCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">JSC [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_JSCMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">JSC.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredStockPurchasePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred stock purchase price per share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredStockPurchasePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred stock purchase price per share.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PreferredStockPurchasePricePerShare_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Stock Purchase Price Per Share</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AtTheMarketProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">At The Market Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AtTheMarketProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">ATM Program.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AtTheMarketProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ATM Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidatedEntitiesDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidated Entities [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Income Tax Expense (Benefit), Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Expense (Benefit)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Benefit from income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeTaxExpenseBenefit_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Provision for income taxes</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Measurement Frequency [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock, Shares Outstanding</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueRevenueRecognized1_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue, Revenue Recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DeferredRevenueRevenueRecognized1_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Accumulated Other Comprehensive Income (Loss), Net of Tax, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income (Loss), Net of Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated other comprehensive income</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payments to Acquire Property, Plant, and Equipment, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments to Acquire Property, Plant, and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchases of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Shares, Granted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_Assets_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedCommonStockActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Unvested common stock activity.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedCommonStockActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Unvested common stock activity [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_UnvestedCommonStockActivityMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unvested Common Stock Activity</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DiscoveryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Discovery program member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DiscoveryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Discovery Program [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_DiscoveryProgramMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discovery Program</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaboration and license agreement member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaboration and License Agreement [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationAndLicenseAgreementMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaboration and License Agreement</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, New Issues</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock in connection with initial public offering, net of issuance costs (in shares)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Temporary Equity, Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Redeemable convertible preferred units, authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_TemporaryEquitySharesAuthorized_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Shares Authorized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Shares, Vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Number of Shares, Vested</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Earnings Per Share, Diluted, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Earnings Per Share, Diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_EarningsPerShareDiluted_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net loss per share attributable to common stockholders - diluted</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Segments [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingSegmentsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Segments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Title and Position [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_CityAreaCode_lbl" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherThanTemporaryImpairmentsLossDebtSecuritiesPortionRecognizedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment loss recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherThanTemporaryImpairmentsLossDebtSecuritiesPortionRecognizedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Other Than Temporary Impairments Loss Debt Securities Portion Recognized In Earnings</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_OtherThanTemporaryImpairmentsLossDebtSecuritiesPortionRecognizedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Other-than-temporary impairments loss debt securities portion recognized in earnings.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Counterparty Name [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Value, Employee Stock Purchase Plan</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodValueEmployeeStockPurchasePlan_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock under employee stock purchase plan (ESPP)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period, Shares, Restricted Stock Award, Gross</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vesting of restricted stock units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property, Plant and Equipment, Net, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Property, Plant and Equipment, Net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment, net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Loss from operations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Income (Loss)</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Operating loss</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Deficit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CashAndCashEquivalentsAxis_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash and Cash Equivalents [Axis]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Share-Based Payment Arrangement, Noncash Expense, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Noncash Expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Recognized compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Stock Issuance Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments of initial public offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfStockIssuanceCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payments of initial public offering costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AdditionalEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional equity consideration shares received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AdditionalEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Additional equity consideration shares received.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AdditionalEquityConsiderationSharesReceived_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Additional Equity Consideration Shares Received</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Target two member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Target Two [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_TargetTwoMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Target Two</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease, Liability, Noncurrent</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-current portion of operating lease liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Inputs, Level 1 [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueInputsLevel1Member_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Level 1</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DisclosureTextBlockAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Disclosure Text Block [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Financing Activity, Including Discontinued Operation</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivities_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net cash used in financing activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Investments, Fair Value Disclosure, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Investments, Fair Value Disclosure</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_InvestmentsFairValueDisclosure_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated fair value of investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Nonoperating Income (Expense) [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other income (expense):</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureMilestonePaymentsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Potential future milestone payments receivable</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_PotentialFutureMilestonePaymentsReceivable_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Potential future milestone payments receivable.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextblock_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Schedule of accrued expenses and other current liabilities.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextblock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Accrued Expenses And Other Current Liabilities Table TextBlock</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextblock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Accrued Expenses and Other Current Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_ScheduleOfAntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareTextBlock_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Outstanding Potentially Dilutive Securities that have been Excluded from Calculation of Diluted Net Loss Per Unit</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Corporate Debt Securities [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_CorporateDebtSecuritiesMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate Debt Obligations</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_DebtSecuritiesAvailableForSaleTable_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Debt Securities, Available-for-Sale [Table]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityInteractiveDataCurrent_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Interactive Data Current</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncomeStatementLocationDomain_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Statement of Income Location, Balance [Domain]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award plan modification incremental compensation cost not yet recognized.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Plan Modification Incremental Compensation Cost not yet recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostNotYetRecognized_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expenses relating to modification expected to be recognized</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash flows from operating activities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtAndModernaRtProgramsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Moderna DT and Moderna RT programs.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtAndModernaRtProgramsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Moderna DT And Moderna RT Programs [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ModernaDtAndModernaRtProgramsMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Moderna DT and Moderna RT Programs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesB1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Series B-1 Preferred Stock.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesB1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Series B1 Preferred Stock [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_SeriesB1PreferredStockMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Series B-1 Preferred Units</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accretion (Amortization) of Discounts and Premiums, Investments</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccretionAmortizationOfDiscountsAndPremiumsInvestments_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accretion of discounts on available-for-sale marketable securities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Increase (Decrease) in Other Noncurrent Liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_IncreaseDecreaseInOtherNoncurrentLiabilities_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other non-current liabilities</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in fair value included in other income (expense), net</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings_lbl" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Loss related to change in fair value</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WaveTwoTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Wave 2 target member.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WaveTwoTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Wave Two Target [Member]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_WaveTwoTargetMember_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Wave 2 Target</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenuesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenues [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Collaborations revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_CollaborationsRevenue_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Collaborations revenue.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="dei_LocalPhoneNumber_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="srt_BoardOfDirectorsChairmanMember_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Board of Directors</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedPaymentArrangementModificationExpenseCostNotYetRecognizedPeriodForRecognition_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Share-based payment arrangement, modification expense, cost not yet recognized, period for recognition.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedPaymentArrangementModificationExpenseCostNotYetRecognizedPeriodForRecognition_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Share-Based Payment Arrangement, Modification expense, Cost Not yet Recognized, Period for Recognition</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ShareBasedPaymentArrangementModificationExpenseCostNotYetRecognizedPeriodForRecognition_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected recognized period</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfFinancingCosts_lbl" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Payment of deferred financing costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfFinancingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Payments of Financing Costs</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_PaymentsOfFinancingCosts_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Payments of Financing Costs, Total</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedPurchasesOfPropertyAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Accrued purchases of property and equipment.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedPurchasesOfPropertyAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Purchases of Property and Equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_AccruedPurchasesOfPropertyAndEquipment_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued purchases of property and equipment</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_AccountingPoliciesAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Policies [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/documentation">Reconciliation of cash, cash equivalents and restricted cash.</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Reconciliation of cash, cash equivalents and restricted cash [Abstract]</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="mgx_ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reconciliation of cash, cash equivalents and restricted cash</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/label">Revenue from Contract with Customer, Excluding Assessed Tax</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaboration revenue</link:label>
          <link:label xml:lang="en-US" xlink:type="resource" xlink:label="us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_lbl" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total collaboration revenue</link:label>
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  <xsd:element id="mgx_AccruedPurchasesOfPropertyAndEquipment" name="AccruedPurchasesOfPropertyAndEquipment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_EstimatedContractConsideration" name="EstimatedContractConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_WarrantsPurchased" name="WarrantsPurchased" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ModernaRtProgramMember" name="ModernaRtProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ReimbursableExpenses" name="ReimbursableExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganization" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganization" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_CommonStockIssuableUponSettlementOfProfitsInterestsMember" name="CommonStockIssuableUponSettlementOfProfitsInterestsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CollaborationsRevenue" name="CollaborationsRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_MetagenomiLLCMember" name="MetagenomiLLCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ShareBasedPaymentArrangementModificationExpenseCostNotYetRecognizedPeriodForRecognition" name="ShareBasedPaymentArrangementModificationExpenseCostNotYetRecognizedPeriodForRecognition" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_VestedProfitsInterestsMember" name="VestedProfitsInterestsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_FacilitiesAndOverheadCosts" name="FacilitiesAndOverheadCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_AggregatePurchasePrice" name="AggregatePurchasePrice" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_OptionExerciseFeePaid" name="OptionExerciseFeePaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganizationWeightedAverageExercisePrice" name="ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExchangedForVestedAndUnvestedCommonStockInConnectionWithTheReorganizationWeightedAverageExercisePrice" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_TemporaryEquityStockIssuedSharesConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering" name="TemporaryEquityStockIssuedSharesConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_WeightedAverageNumberOfSharesOutstandingBasicBeforeAdjustments" name="WeightedAverageNumberOfSharesOutstandingBasicBeforeAdjustments" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_RestrictedStockSubjectToFutureVestingMember" name="RestrictedStockSubjectToFutureVestingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_UnvestedRestrictedCommonStockMember" name="UnvestedRestrictedCommonStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ExercisePaymentReceived" name="ExercisePaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CostSharePercentageDescription" name="CostSharePercentageDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_CommonStockWarrantExercisable" name="CommonStockWarrantExercisable" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="mgx_FinalPaymentToBeForfeited" name="FinalPaymentToBeForfeited" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_FutureDevelopmentMilestonePaymentsToBeReceived" name="FutureDevelopmentMilestonePaymentsToBeReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_StockSharesCanceled" name="StockSharesCanceled" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_MilestonePaymentReceived" name="MilestonePaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_LicenseFee" name="LicenseFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_EmployeeStockPurchasePlanMember" name="EmployeeStockPurchasePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_FairValueOfInvestmentReceivedAsCollaborationConsideration" name="FairValueOfInvestmentReceivedAsCollaborationConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ReductionInVariableConsideration" name="ReductionInVariableConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CoDevelopAndCoCommercializeLicensedProductsMember" name="CoDevelopAndCoCommercializeLicensedProductsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_DenominatorAbstract" name="DenominatorAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_PurchaseOfPreferredStockAdditional" name="PurchaseOfPreferredStockAdditional" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_OptionPriceEstimatedFairValuePercentageOnDateOfGrant" name="OptionPriceEstimatedFairValuePercentageOnDateOfGrant" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_RemeasurementOfOperatingRightOfUseAssetAndLeaseLiability" name="RemeasurementOfOperatingRightOfUseAssetAndLeaseLiability" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_TechnologyMilestoneFeesReceived" name="TechnologyMilestoneFeesReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_AmortizationOfNonCashCollaborationsRevenue" name="AmortizationOfNonCashCollaborationsRevenue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_CostSharingAllocationExpense" name="CostSharingAllocationExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_PotentialFutureMilestonePaymentsReceivable" name="PotentialFutureMilestonePaymentsReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_NonRefundableUpfrontCollaborationPaymentReceived" name="NonRefundableUpfrontCollaborationPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganization" name="IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganization" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextblock" name="ScheduleOfAccruedExpensesAndOtherCurrentLiabilitiesTableTextblock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ManufacturedComponentsProceeds" name="ManufacturedComponentsProceeds" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CollaborationAndLicenseAgreementMember" name="CollaborationAndLicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_TargetTwoMember" name="TargetTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CommonStockPurchaseAdditional" name="CommonStockPurchaseAdditional" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganizationShares" name="IssuanceOfCommonStockAndRestrictedCommonStockInExchangeForProfitsInterestsUponReorganizationShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostNotYetRecognized" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardPlanModificationIncrementalCompensationCostNotYetRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_SeriesAConvertiblePreferredStockMember" name="SeriesAConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_RoyaltyTermExpirationPeriod" name="RoyaltyTermExpirationPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_SalesBasedMilestonesToBeReceived" name="SalesBasedMilestonesToBeReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_PercentageAddedToCostOfGoodsThatRepresentsPriceOfManufacturedComponents" name="PercentageAddedToCostOfGoodsThatRepresentsPriceOfManufacturedComponents" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_BrianCThomasPhDMember" name="BrianCThomasPhDMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities" name="InitialPublicOfferingCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ReimbursementForResearchCosts" name="ReimbursementForResearchCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_WarrantExercisable" name="WarrantExercisable" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_MetagenomiIncMember" name="MetagenomiIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_PotentialFutureSalesBasedMilestonesReceived" name="PotentialFutureSalesBasedMilestonesReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_TemporaryEquityStockIssuedValueConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering" name="TemporaryEquityStockIssuedValueConversionOfRedeemableConvertiblePreferredStockToCommonStockUponInitialPublicOffering" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_IonisMember" name="IonisMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract" name="ReconciliationOfCashCashEquivalentsAndRestrictedCashAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ContractConsiderationAmount" name="ContractConsiderationAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_NonRefundableUpfrontPaymentReceived" name="NonRefundableUpfrontPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_PreferredStockPurchasePricePerShare" name="PreferredStockPurchasePricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_AccruedPersonnelRelatedExpensesCurrent" name="AccruedPersonnelRelatedExpensesCurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_StockholdersEquityLineItems" name="StockholdersEquityLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ExercisePaymentReserve" name="ExercisePaymentReserve" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_WarrantsPurchasedPricePerShare" name="WarrantsPurchasedPricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_IncreaseInVariableConsideration" name="IncreaseInVariableConsideration" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ExercisePaymentReceivable" name="ExercisePaymentReceivable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_AccruedResearchAndDevelopmentExpenses" name="AccruedResearchAndDevelopmentExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ProvisionForIncomeTaxes" name="ProvisionForIncomeTaxes" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ReimbursableExpenseReceived" name="ReimbursableExpenseReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCanceledInConnectionWithTheReorganizationInPeriod" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsCanceledInConnectionWithTheReorganizationInPeriod" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_PurchaseOfPreferredStock" name="PurchaseOfPreferredStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_SalesBasedMilestonesReceived" name="SalesBasedMilestonesReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_AffiniTTherapeuticsIncMember" name="AffiniTTherapeuticsIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_SeriesA4PreferredStockMember" name="SeriesA4PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ConversionOfStockSharesOutstaning" name="ConversionOfStockSharesOutstaning" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ExtendedReasearchTerm" name="ExtendedReasearchTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_AdditionalExploratoryCostReimbursementsAmount" name="AdditionalExploratoryCostReimbursementsAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_FairValueOfInvestmentPurchasedInPreferredStockPurchaseAgreement" name="FairValueOfInvestmentPurchasedInPreferredStockPurchaseAgreement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_NumeratorAbstract" name="NumeratorAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_JSCMember" name="JSCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CollaborationAgreementUpfrontPaymentReceived" name="CollaborationAgreementUpfrontPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ContingentConsiderationClassifiedAsEquityFairValueDisclosureAdditional" name="ContingentConsiderationClassifiedAsEquityFairValueDisclosureAdditional" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ExerciseFeeDescription" name="ExerciseFeeDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_PotentialFutureTargetSelectionFee" name="PotentialFutureTargetSelectionFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_WaveTwoTargetMember" name="WaveTwoTargetMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_FutureRegulatoryApprovalMilestonePaymentsReceived" name="FutureRegulatoryApprovalMilestonePaymentsReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_DevelopmentOptionAndLicenseAgreementMember" name="DevelopmentOptionAndLicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_OtherIncomeExpenseMember" name="OtherIncomeExpenseMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_SeriesA5PreferredStockMember" name="SeriesA5PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_StrategicCollaborationAndLicenseAgreementMember" name="StrategicCollaborationAndLicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_DescriptionOfTerminationOfAgreement" name="DescriptionOfTerminationOfAgreement" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_WeightedAverageNumberOfUnvestedShares" name="WeightedAverageNumberOfUnvestedShares" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ModernaCollaborationAgreementAndModernaConvertiblePromissoryNoteAgreementMember" name="ModernaCollaborationAgreementAndModernaConvertiblePromissoryNoteAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CollaborationAgreementInitialResearchTerm" name="CollaborationAgreementInitialResearchTerm" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_CommonStockExercisePricePerShare" name="CommonStockExercisePricePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_CertainVestingConditionsMember" name="CertainVestingConditionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_DevelopmentOptionAndLicenseAgreementUpfrontEquityConsiderationEstimatedFairValue" name="DevelopmentOptionAndLicenseAgreementUpfrontEquityConsiderationEstimatedFairValue" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_DtCoCoProgramMember" name="DtCoCoProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_LongTermInvestmentsMember" name="LongTermInvestmentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_SeriesA3PreferredStockMember" name="SeriesA3PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_EquityTable" name="EquityTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_EstimatedTransactionPrice" name="EstimatedTransactionPrice" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ModernaDtProgramMember" name="ModernaDtProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_StockOptionAndIncentivePlanMember" name="StockOptionAndIncentivePlanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_AcuitasLicenseAgreementMember" name="AcuitasLicenseAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ProfitsUnitsActivityMember" name="ProfitsUnitsActivityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ExtendedResearchTerms" name="ExtendedResearchTerms" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_IncreaseDecreaseInDeferredRevenueAndCollaborationAdvances" name="IncreaseDecreaseInDeferredRevenueAndCollaborationAdvances" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ResearchAndDevelopmentCostReceived" name="ResearchAndDevelopmentCostReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_SeriesA1PreferredStockMember" name="SeriesA1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_SelectedTargetMember" name="SelectedTargetMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_EmployeesEligibleAnnualCompensation" name="EmployeesEligibleAnnualCompensation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_FututeSalesBasedMilestonesToBeReceived" name="FututeSalesBasedMilestonesToBeReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_IncentiveStockOptionsAndNonQualifiedStockOptionsMember" name="IncentiveStockOptionsAndNonQualifiedStockOptionsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_UpfrontEquityConsiderationReceived" name="UpfrontEquityConsiderationReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ProfitsInterestsMember" name="ProfitsInterestsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_DeferredFinanceIssuanceCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities" name="DeferredFinanceIssuanceCostsIncludedInAccountsPayableAccruedExpensesAndOtherCurrentLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ModernaMember" name="ModernaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ReimbursableInternalCostsAndOutOfPocketCostsIncurred" name="ReimbursableInternalCostsAndOutOfPocketCostsIncurred" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ResearchAndDevelopmentSuppliesAndServices" name="ResearchAndDevelopmentSuppliesAndServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CatchUpThresholdAmountBasedOnEstimatedFairValueOfCommonUnit" name="CatchUpThresholdAmountBasedOnEstimatedFairValueOfCommonUnit" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false"/>
  <xsd:element id="mgx_VittoriaInvestmentMember" name="VittoriaInvestmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_AnnualResearchAndDevelopmentCostsReimbursement" name="AnnualResearchAndDevelopmentCostsReimbursement" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ContractConsiderationTransactionCost" name="ContractConsiderationTransactionCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_PurchasesPercentageOnEmployeesEligibleAnnualCompensation" name="PurchasesPercentageOnEmployeesEligibleAnnualCompensation" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_ReimburableInternalCostsAndOutOfPocketCostsIncurredPayableInQuarterlyInstallments" name="ReimburableInternalCostsAndOutOfPocketCostsIncurredPayableInQuarterlyInstallments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CommonStockIssuableUponConversionOfRedeemableConvertiblePreferredStockMember" name="CommonStockIssuableUponConversionOfRedeemableConvertiblePreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_SeriesB1PreferredStockMember" name="SeriesB1PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ReclassificationOfDeferredOfferingCostsPaid" name="ReclassificationOfDeferredOfferingCostsPaid" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_AtTheMarketProgramMember" name="AtTheMarketProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CatchUpMember" name="CatchUpMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_PreferredUnitsMember" name="PreferredUnitsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_OtherThanTemporaryImpairmentsLossDebtSecuritiesAvailableForSale" name="OtherThanTemporaryImpairmentsLossDebtSecuritiesAvailableForSale" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_DiscoveryProgramMember" name="DiscoveryProgramMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ModernaTxIncMember" name="ModernaTxIncMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_FutureRegulatoryMilestonePaymentsToBeReceived" name="FutureRegulatoryMilestonePaymentsToBeReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_CreditsRecognizedWithinResearchAndDevelopmentExpenses" name="CreditsRecognizedWithinResearchAndDevelopmentExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_PercentageOfAppointmentRight" name="PercentageOfAppointmentRight" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_AmortizationOfContractConsiderationAmount" name="AmortizationOfContractConsiderationAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_FutureRegulatoryApprovalMilestonePaymentReceived" name="FutureRegulatoryApprovalMilestonePaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_UpfrontEquityConsiderationSharesReceived" name="UpfrontEquityConsiderationSharesReceived" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_SeriesA2PreferredStockMember" name="SeriesA2PreferredStockMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ModificationUnderAscSevenOneEightMember" name="ModificationUnderAscSevenOneEightMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_AtTheMarketSalesAgreementRemainingCapacity" name="AtTheMarketSalesAgreementRemainingCapacity" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_OtherCollaborationRevenueMember" name="OtherCollaborationRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_CommonStockForFutureIssuanceDescription" name="CommonStockForFutureIssuanceDescription" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_UpfrontPaymentReceived" name="UpfrontPaymentReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_DevelopmentRegulatoryAndSalesMilestonePayments" name="DevelopmentRegulatoryAndSalesMilestonePayments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ProfitInterestUnitMember" name="ProfitInterestUnitMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true"/>
  <xsd:element id="mgx_ChangeInFairValueOfLongTermInvestments" name="ChangeInFairValueOfLongTermInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_ChangeInFairValueOfLevel3FinancialAssets" name="ChangeInFairValueOfLevel3FinancialAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_PurchaseOfCommonStock" name="PurchaseOfCommonStock" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_CollaborationAdvance" name="CollaborationAdvance" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_AdditionalEquityConsiderationSharesReceived" name="AdditionalEquityConsiderationSharesReceived" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_DescriptionOfTerminationOfRoyaltyTerm" name="DescriptionOfTerminationOfRoyaltyTerm" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false"/>
  <xsd:element id="mgx_TargetSelectionFee" name="TargetSelectionFee" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
  <xsd:element id="mgx_FutureDevelopmentalMilestonePaymentsReceived" name="FutureDevelopmentalMilestonePaymentsReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_CostSharingPayables" name="CostSharingPayables" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_ExercisePayment" name="ExercisePayment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit"/>
  <xsd:element id="mgx_AmortizationOfCollaborationAdvanceExpense" name="AmortizationOfCollaborationAdvanceExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit"/>
</xsd:schema>
